Oil filter



NV 3, 19412- l H. G. KAMRATH 2,301,121

' OIL FILTER Filed July 13,V 1940 Snnentor Patented Nov. 3, 1942 UNITED STATES PATENT OFFICE OlIL FILTER corporation of Delaware Application July 13, 1940, Serial No. 345,313

1 Claim.

Vhaving perforations formed by pressing the metal from the inside so that the metal on the outside will leave sharp edges. The bag is pulled over the column and is over twice as long as the column so that the end of the bag will extend a distance below the column at least the full length thereof. A filtering material is then applied around the bag Where it surrounds the column and the bag is then inverted or turned on itself `and pulled up over the outside of the filtering material. The outer end, or the end which is pulled over the filtering material, is then positioned over the inner end and tucked in between the inner end and the column so that the sharp metal edges of the perforations will retain the end of the bag.

n the drawing Figure `1 is a view of the central perforate column with the bag therebelow and before it is pulled over the column. Figure 2 is a view of the same parts, but with the bag pulled overthe column.

Figure 3 is a view of the parts of Figures 1 and 2, but showing the filtering material applied and with the lower part of the View showing the extent to which the bag may stretch or expand.

Figure 4 is a partial sectional view of the top of the nlten'ng unit showing how the bag ends are secured in place.

Figure 5 is a view of the filter containerwith parts broken away and showing the bag in section applied and mounted inside the container.

Referring to the drawing, the numeral 2 indicates a tubular column, and 4 the bag of the invention. The column 2 is provided with perforations entirely around its circumference, these perforations being formed by pressing the metalfrom the inside outwardly whereby sharp points are formed on the metal around the perforations. 'lhe perforations are indicated at 6 and in forming these perforations the outside part thereof forms sharp edges or teeth to retain the bag.

The bag 4 is then pulled up over the column 2 as shown in Figure 2, and the -upper and inner end 8 is caused to extend a short distance above the upper end lll of the column.

A filtering material I2 of any suitable type is then packed around the bag lwhere it surrounds the column 2 shown in Figure 3. This filtering material may be mineral wool, wood pulp, paper pulp, cotton linters or cotton batting, or the like.

The bag 4 is of fabric and is capable of considerable stretch and with the ltering material I2 packed as shown in Figure 3 the lower or free end of the bag 4 is then inverted or folded back on itself and drawn upwardly around the outside of the filtering material I2. The extension 8 of the top of the bag is placed over the top of the filtering material l2 and the free end I4 of the bag is positioned over the free or inner end 8 and the end I4 tucked down in between the upper end I0 of the cylindrical part 2 and the inner end ofl the bag adjacent the cylinder. The sharp edges on the perforations 6 will tightly hold the end I4 of the bag. This structure is best shown in Figure 4.

The filtering unit indicated as a whole at U in Figure 5 is now positioned in a filtering container I6 having a truncated conical bottom I8 and a removable cover 20. The oil enters at the inlet 22 and leaves from the outlet 24 and the oil passes through the filter in the manner described in the copending application of John F. Houston for an Oil filter, Serial No. 345,324, filed July 13, 1940. The numeral 25 designates a removable end of the filtering frame, and the numeral 2B the stationary end. A handle 28 is provided to remove the unit from the container I8.

The stationary plate 26 has an upwardly pro-A jecting cylindrical member 30 secured thereto and this element projects into the interior of the cylinder or column 2 to hold it in place.

I claim:

In a filter, a perforated metal central column, Said perforations being formed by pressing the metal of the column from the inside outwardly to form sharp edges on the pressed out metal around the openings, an elongated fabric filter bag over the entire length of the column, said bag being considerably longer than the column and having the inner end thereof positioned around one end of the column and the other or outer end extending freely beyond the other end of the column, a filtering material surrounding the bag where it :tits over the column, the free end of said bag being reversed on itself and drawn backward over the outside of the filtering material to cause the bag to cover the exterior and ends of the filtering material. the .tree or outer end of said bag being held in place by tuck ing it over the inner end between the column and inner end to enable the sharp edges to grip the fabric tightly to hold the fabric in place.

HERBERT GKAMRATH., 

